Buoyancy-indicator.



- G. A. SPRATT.

BUOYANGY INDICATOR.

APPLICATION FILED FEB. za, 1910.

Patented Jan. 14, 1913.

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UNITED sTATEs PATENT oEEIoE;

oEoEGE A. SPEATT, or coATEsvILLE, PENNSYLVANIA.

EOYANCYLINDIcATQE.

To all 'whom it may-concern.' f

Be it known that I, GEORGE A. SPRA'rr, a

. citizen of the United States, and a resident of Coatesville, Chestercounty, Pennsylvania, have invented a 'Buoyancy-Indicator,

` of which the followingisy a specification.

My invention relates to aeroplane's. and accessories therefor; and theobject'of my inventio'ngis to provide means for indicating to theoperator the approximateforce'of the wind andlconsequently itsapproximate eX- tent of bubyancy or lifting power; the term Wind as hereused referring to therelative speed Abetween air and aeroplane. Aknowledge of the amount of the available supporting power of the wind,and the actual Iamount of supporting `power being used as support, ishighly desirable at all times, and especially so in making a landing,for contact with the ground should be made whenl the supporting pressurejust equals the weight of the aeroplane. The aeroplane should not bedriven against the ground by an excessive speed nor be allowed to fallagainst the ground as a result of too slow a speed. It is essential forsafe aviationJ to be able to recognize and acquire that vSpeed at whichthe pressures will just supportthe weight. y

My invention consists of a speed indicator so vcorrelated to the weightof the aeroplane that it shows at a vving powerl of the win in terms othe weight of the aeroplane. It presents a min- 5 imum of weight and ofresistance to advance throughthe air. It comprises a tell-tale in theform of a bladed fan or propeller lof light construction to bevmountedat some convenient point upon the aeroplane in advance of theoperator. Other features of my`invention will be pinted out hereinafter,reference being had tothe accompanying drawing, in which: Figui-e 1,'is'a pers ective view illustrat- `ing a 'conventional orm of a vbiplaneto "which my invention may beapplied; Fig. 2,

*isa'n enlarged perspective view of thev buoyancy indicator structureillustrated in Fig.

FI; 'Fi-g.' 3, is a view illustrating va modifica- 00 'tion embodying myinvention, and Figs. 4 and 5, are views of details of my invention..

i 'supported shaft or spindlel so mounted as glance, the sup ort--speeiacation of Letters raient. A Patented Jan, 14, 1913, Applicationmed February 23, 1910. Serial No. 545,36-9.

for the purpose, and these blades are free to rotate on the splndle;being arranged to turn agamst the tension of-a spring, preferablycoiled, indicated at 3, one end of'which is connected'to the spindle andthe other end to said blades Atthe opposite end of the spindle, tailvanes 5 may be employed, triangular inzshape, extending to a point atthe rear end of the spindle, and connected at their inner ends tocross-bars 6 carried by the spindle; the ends of which may be connectedpto the-spindle by cords 7. At the forward end of the spindle, a Weight8 may be placed. If desired, the blades may be of distinctive colors.

The spindle 1 is supported by a swivel or universal joint carried by asuitable standard 9. `As shown in the drawings, this consists of a yokeby cords 11 within a ring 12 mounted on the 'standard 9 which may besecured at a convenient point y with respect to theaeroplan'e lstructure directly within the'vision ofy the operator. Ivhave showninfull lines o'n Fig. l, the preferred position. of the indicator andin'dot-ted lines other positions in which "such indicator may bevplaced. The form of swivel or universal joint shown may be ernployed,but I do notwish to be limited to the precise construction, since manyother forms of swivel or universal joint connections, all within thescope of my invention maybe employed. u

The tension of the spring is-preferably therefore, will v member 10,suspended whether or not the wind or air currents are above or lbelowthe degree of force or velocity necessary to provide sutiicient buoyancyto sustain the aeroplane.l j,

'In the form of structure shown in Fig. 3 the tail vanes are omitted andthe blades are `mounted on a spindle supported in substantially the samemanner as that indicated in Figs. 1 and 2, with the exception that theblades are placed `at the rear and are suiicient to counterbala'nce theweight disposed 1, blades 2.arej0urna1ed-5fbyon the otherside of thesupport and perform j substantially the same functions as the tail;

I block 14, interposed between the spindle 1 and said springror by anyother convenient@I means affording a rigid connection between .bladesmaybe colored black and white, or

.varies in addition to those described `with lthe length of spring,since any addition to v higher speed for support. Thiscan be done 1.Then jby revolvingl the clamp once `coil of spring and moving the clampalong sen-t the speed increase demanded bya definite load added. Forinstance, one coil orA accomplished byv providing a set screw 15, toengage the ,spindle when the "Weight" is 'finally positioned at thedesired point.

. entering the hole in the weight alongwith v is a safetydevice, lbywhich the supporting 'At n'o speed, ae., 1n a calm, thel white blade,for instance, should `be down and lie' respect to the structure shown inFigs. 1 and 2. The mounting for the spindle shown -in Fig. 3-may besubstantially the same as that shown in Fig. 2, or any other mountingthat. Will provide a yielding support for the spindle may be employed.

I may also provide means for shortening the weight of an aeroplane'demands a by fastenmg the sprlng to the spindle by means 'of a runningclamp 13 having a set screw 14, l instead of fastening the springpermanently tothe spindle as shown in Fig.

around the spindle thereby takingup one the spindle, the spring wouldtighten (z'. e., increase) the tensional resistance to repreone-halfcoil or any proportionate and necessary amounty as the `case might be,would be taken up for each 100 lbs. added to the load. The clamp isnoted as a running clamp to convey the meaning that the spring may beshortened by vadjusting the clamp alone, and the angle of the blades,when at rest,is unaltered by such shortening of the spring.

The spring may be held to the clamp by a these parts when the clamp isadjusted withA respect tothe spindle.

It may also be desirable' to provide means for adjusting the weight 8.This may be Other means may be provided to accomplish the same purpose,for instance a wedge the spindle mightbe just as serviceable and insome. instances as satisfactory.

The Amainl purpose of my invention is to assist the begmner. My improvedindicator pressures or amount ofv buoyancy at ,f the aviators command.isryisually indicated in` proportions of the total weight of the loadcarried. It is carried upon the aeroplane in advance v ofthe aviator andin the most direct range or line of his vision. The

otherr easily distinguished, distinctive colors, red and green, etc.

in visualline, parallel with the supportingy post;` The spring should beof such strength revolution, the aeroplane can rise. Any

that when a speed just suflicient to support the mail load has' beennaines the pres# sures on the blades should cause one completerevolution. A greater speed will continue 'to tighten this spring and alesser speed will allow 'the spring to turn the blades toward theiroriginal position.

My buoyancy indicator is also al guide to the wind direction. Its usemay be described as follows: In starting, the aeroplane should head to`the oncoming Wind as indicated by this jinstrument.- If the windpresses the blades one-fourth of a revolution, one-fourth If the bladesindicate less than a revolution While in flight, the supportingpressures are insuficient for support and the machine slumps.

In preparing to alight, if the blades show less than a revolution; saythree-fourths of a revolution at the time of alighting, the shock willbethat of one-fourth of the total weight descending.` If they show' sayone and vone-quarter revolutions at the instant of striking the earth,thereis a momentum of one-quarter of the weight of the machine ,thatmust be` overcome by the contact.

I claim:

1. In a buoyancy indicator for aeroplanes, the combination .of a supportonstandard, a ring carried at the upper end of the same, a

yoke suspended within said ring and capable of universal movementtherein, a spindle carried by said yoke, a blade mounted for rotationupon said spindle,and means for y regulating the movement of saidiblade.

2.- In-a buoyancy indicator for aeroplanes, the combination of a supportor stan a yoke suspendedwithin said ring .for unlversal'movement, aspindle carriedby said yoke, a freely movable bladed member journaledthereon, tension means for sail bladed member vcomprising a springhaving one end connected to the spindle and the opposite end connectedtothe bladed member, and a weight! carried by said spindle.

. 3. p In a buoyancy indicator for aeroplanes, the combination of asupport or standard, a rin carried by the same, a yoke suspended wit insaid ring for universal movement, a spindle carried by said yoke, abladed mem- Fbei: journaled thereon and freely movab1e,.

means for keeping the structure headed into ard, a Y HV ring-carriedbythe upper end of the same,

the wind comprising a plurality of vanes carried by the spindleA at oradjacent one end of the same, and a spring having one end connected tothe spindle and the opposite end connected to the bladed member forimparting tension'to tlie latter and regulating movement `of the same.

4. In a buoyancy indicator for faeroplanes, the vcombination of aysupport or standard, Ia y .ring `carried by the same, .a yoke member,:flexible cords carried by :said ring for :supporting said yoke memberthe ring Q and permitting universal movement of the same, a spindlecarried by said yoke, a rotatably mounted -blade on said spindle, andadjustable. means between said blade and spin- (lle for regulating themovement of said blade. 1

In testimony whereof, I have signed my two subscribing witnesses.

GEORGE A. SPRATT.

name to this specification, in the presence of 2

